I am installing a new stereo in my 99 grand prix. I have the big wiring harness connected in with the radio. But theres a 2nd smaller one with 3 wires, The Stereo turns on there is just no noise. Its all hooked up correct ive double checked it a few times. Im thinkin its something with that theft lock. Anything would be great.

ther is a factory amplifier in the trunk youll have to bypass it or get it to turn on the second hanesss is for the steering wheel controls

do you know where the factory amplifier is located in the trunk?

PM me with the last 8-digits of your vin to verify you have the factory Bose system or look for option code U85 on the SPID label on the underside of the trunk. Only the Bose system has the external separate amp, so if you don't have that option, you have a different issue.

open the trunk look on the drivers side next to where the speakers are and there should be a black box.

it doesnt have the bose system? i think. I cant find any black box in the trunk.

if you have one it is mounted on the roof of the trunk by your rear speakers

The car doesn't have the Bose system (he PM'ed me and the vin confirms it). My 99 had an issue with the rear speakers going in and out, and finally they quit altogether, and it was the speakers that were bad. Did this problem only crop up after the stereo switch, or was it the reason for the switch?